# 範例2 ## 一般印數字 ClassDemo01.java(下稱建構子區) ```java= public class ClassDemo01 { public int getNumber() { return new Inner().setNumber() + 100; } // 內部類別 private class Inner { private int a = 123; public int setNumber() { return a; } } } ``` MainTest.java(下稱測試區) ```java= public class MainTest { @Test public void test01() { ClassDemo01 cd = new ClassDemo01(); int z = cd.getNumber(); System.out.println(z); } } ``` ## 輸入一個字元做選擇 建構子區 ```java= public class ClassDemo01 { public int getNumber(char x) { if (x == 'A') { return new Inner().setNumber(); } else if (x == 'B') { return new Inner().setNumber1(); } else if (x == 'C') { return new Inner().setNumber2(); } else { return 0; } } // 內部類別 private class Inner { private int a = 123; public int setNumber() { return a; } public int setNumber1() { return a + 23; } public int setNumber2() { return a + 100; } } } ``` 測試區 ```java= public class MainTest { @Test public void test01() { ClassDemo01 cd = new ClassDemo01(); int z = cd.getNumber('A'); System.out.println(z); } } ```